These caterpillars devastated my rhodedendron last year. It did flower this year and its leaves are just recovering. However I've just today seen new caterpilars (so far only 3-4mm long) all over it again. Any advice on what I can spray on it to get rid of them?

The top leaves on my acer are losing colour and browing at the edges. Is it infected with something or is it due to weather - too windy? too sunny? The leaves bwlow the top ones are growing fine and nice and green. Its in the pot below which has just started showing strange patterns on it so not sure if this indicates some fungal infection?

My rhodedendron has been nearly half eaten (leaves mostly) by caterpillars - looking on the internet, these are azalea caterpillars. I can find lots online about these caterpillars, but I can't find what to do with my rhodedendron to help it survive. I have plucked off the caterpillars. Do I need to cut back the rhodedendron or do anything else to improve its health/look??